Jonas and Levinas are two names intimately associated with contemporary ethics. While they are not unequivocally linked to utopian thought, they have nonetheless decisively contributed to rethinking utopia. In this essay, I seek in these two authors and their texts the elements of a critical reading that would allow us to analyse and reconsider the question of utopia as it is formulated by thinkers more directly associated with it, such as Bloch, Buber and Bacon.

Para se abordar a questão da verdade, no pensamento de Levinas, faz-se necessário procurar antes o seu fundamento que, na ética como filosofia primeira, é a justiça. Em seguida, é preciso fazer o caminho da fenomenologia levinasiana em diálogo com as fenomenologias de Husserl e Heidegger, além de passar pelo modo como Kierkegaard compreende ética. Levinas busca o Sentido dos sentidos, distanciando-se de Husserl para quem o sujeito é a fonte de todo sentido; mas também se distanciando da ontologia de (...) Heidegger que opera uma redução de tudo ao ser, suprimindo a exceção do Outro. Se Kierkegaard descobriu a interioridade como marca indelével da subjetividade que recusa se perder na obra da totalização, ele não consegue escapar de outra violência que não compreende a exterioridade como vindo de fora de todo Sistema, deixando o ético se perder no geral. A relação ética, tal como Levinas a compreende, é, ao contrário, uma relação de único a único. A significação primeira da Verdade é de ordem ética e não se entende senão em relação com a justiça - retidão do face a face - que a ontologia traduzirá tardiamente como verdade que se mostrará no ser. (shrink)

A minimal constraint on normative reasons seems to be that if some fact is a reason for an agent to φ (act, believe, or feel), the agent could come to know that fact. This constraint is threatened by a well-known type of counterexamples. Self-effacing reasons are facts that intuitively constitute reasons for an agent to φ, but that if they were to become known, they would cease to be reasons for that agent. The challenge posed by self-effacing reasons bears important (...) structural similarities with a range of epistemic paradoxes, most notably the Knowability Paradox. In this article, we investigate the similarities and differences between the two arguments. Moreover, we assess whether some of the approaches to the Knowability Paradox could help solve the challenge posed by self-effacing reasons. We argue that at least two popular approaches to the paradox can be turned into promising strategies for addressing the self-effacing reasons problem. (shrink)

This paper proposes a new dialetheic logic, a Dialetheic Logic with Exclusive Assumptions and Conclusions ), including classical logic as a particular case. In \, exclusivity is expressed via the speech acts of assuming and concluding. In the paper we adopt the semantics of the logic of paradox extended with a generalized notion of model and we modify its proof theory by refining the notions of assumption and conclusion. The paper starts with an explanation of the adopted philosophical perspective, then (...) we propose our \ logic. Finally, we show how \ supports the dialetheic solution of the liar paradox. (shrink)

In this short paper we consider Linnebo's thin/thick dichotomy: first, we show that it does not overlap with the very common one between abstract/concrete objects; second, on the basis of some difficulties with the distinction, we propose, as a possible way out, to move from thin/thick objects to thin/thick concepts.

According to strong composition as identity, the logical principles of one–one and plural identity can and should be extended to the relation between a whole and its parts. Otherwise, composition would not be legitimately regarded as an identity relation. In particular, several defenders of strong CAI have attempted to extend Leibniz’s Law to composition. However, much less attention has been paid to another, not less important feature of standard identity: a standard identity statement is true iff its terms are coreferential. (...) We contend that, if coreferentiality is dropped, indiscernibility is no help in making composition a genuine identity relation. To this aim, we analyse as a case study Cotnoir’s theory of general identity, in which indiscernibility is obtained thanks to a revisionary semantics and true identity statements are allowed to connect non-coreferential terms. We extend Cotnoir’s strategy for indiscernibility to the relation of comaternity, and we show that, neither in the case of composition nor in that of comaternity, indiscernibility contibutes to show that they are genuine identity relations. Finally, we compare Cotnoir’s approach with other versions of strong CAI endorsed by Wallace, Bøhn, and Hovda, and canvass the extent to which they violate coreferentiality. The comparative analysis shows that, in order to preserve coreferentiality, strong CAI is forced to adopt a non-standard semantic treatment of the singular/plural distinction. (shrink)

In this paper we consider the emerging position in metaphysics that artifact functions characterize real kinds of artifacts. We analyze how it can circumvent an objection by David Wiggins (Sameness and substance renewed, 2001, 87) and then argue that this position, in comparison to expert judgments, amounts to an interesting fine-grained metaphysics: taking artifact functions as (part of the) essences of artifacts leads to distinctions between principles of activity of artifacts that experts in technology have not yet made. We show, (...) moreover, that our argument holds not only in the artifactual realm but also in biology: taking biological functions as (part of the) essences of organs leads to distinctions between principles of activity of organs that biological experts have not yet made. We run our argument on the basis of analyses of artifact and biological functions as developed in philosophy of technology and of biology, thus importing results obtained outside of metaphysics into the debate on ontological realism. In return, our argument shows that a position in metaphysics provides experts reason for trying to detect differences between principles of activities of artifacts and organs that have not been detected so far. (shrink)

Following the speech act theory, we take hypotheses and assertions as linguistic acts with different illocutionary forces. We assume that a hypothesis is justified if there is at least a scintilla of evidence for the truth of its propositional content, while an assertion is justified when there is conclusive evidence that its propositional content is true. Here we extend the logical treatment for assertions given by Dalla Pozza and Garola (1995, Erkenntnis, 43, 81–109) by outlining a pragmatic logic for assertions (...) and hypotheses. On the basis of this extension we analyse the standard logical opposition relations for assertions and hypotheses. We formulate a pragmatic square of oppositions for assertions and a hexagon of oppositions for hypotheses. Finally, we give a mixed hexagon of oppositions to point out the opposition relations for assertions and hypotheses. (shrink)

Are identity criteria grounding principles? A prima facie answer to this question is positive. Specifically, two-level identity criteria can be taken as principles related to issues of identity among objects of a given kind compared with objects of a more basic kind. Moreover, they are grounding metaphysical principles of some objects with regard to others. In the first part of the paper we criticise this prima facie natural reading of identity criteria. This result does not mean that identity criteria could (...) not be taken as grounding principles. In the second part, we propose some basic steps towards a conceptual reading of grounding. Such a way of understanding it goes along with an epistemic reading of identity criteria. (shrink)

Commonsense ontology often conflicts with the ontology of our best scientific and philosophical theories. However, commonsense ontology, and commonsense belief systems in general, seems to be remarkably efficient and cognitively fundamental. In cases of contrast, it is better to find a way to reconcile commonsense and ”theoretical” ontologies. Given that commonsense ontologies are typically expressed within natural language, a classical procedure of reconciliation is semantical. The strategy is that of individuating the ”ontologically problematic” expressions of natural language and paraphrasing the (...) sentences in which they appear in a (formal) language whose commitments are compatible with those of our best theories. We believe that this strategy of reconciliation, though quite standard, especially in the philosophical literature, is problematic: for a start, it forces us to conclude that the ”real content” of our commonsense expressions and beliefs is different from what it appears. Commonsense ontology becomes just an illusion. We will thus propose an alternative approach: according to our view, a commonsense ontology is reconciled with a theoretical ontology in case it is shown that the explanation of why we believe in the existence of a problematic entity is compatible with our best theories. We will call this kind of reconciliation ”epistemic”. The advantage of an epistemic reconciliation is that commonsense ontology is treated in its own right and could be taken prima facie. Another advantage of the view is that epistemic reconciliation can be analysed through the notion of explaining away: a commonsense ontology is epistemically reconciled with a theoretical ontology if and only if the problematic entities of the commonsense ontology are explained away by ”respectable” entities of the theoretical ontology. In the final part of the paper, we sketch a formal analysis of explaining away. (shrink)

Following the speech act theory, we take hypotheses and assertions as linguistic acts with different illocutionary forces. We assume that a hypothesis is justified if there is at least a scintilla of evidence for the truth of its propositional content, while an assertion is justified when there is conclusive evidence that its propositional content is true. Here we extend the logical treatment for assertions given by Dalla Pozza and Garola by outlining a pragmatic logic for assertions and hypotheses. On the (...) basis of this extension we analyse the standard logical opposition relations for assertions and hypotheses. We formulate a pragmatic square of oppositions for assertions and a hexagon of oppositions for hypotheses. Finally, we give a mixed hexagon of oppositions to point out the opposition relations for assertions and hypotheses. (shrink)

According to the so-called strong variant of Composition as Identity (CAI), the Principle of Indiscernibility of Identicals can be extended to composition, by resorting to broadly Fregean relativizations of cardinality ascriptions. In this paper we analyze various ways in which this relativization could be achieved. According to one broad variety of relativization, cardinality ascriptions are about objects, while concepts occupy an additional argument place. It should be possible to paraphrase the cardinality ascriptions in plural logic and, as a consequence, relative (...) counting requires the relativization either of quantifiers, or of identity, or of the is one of relation. However, some of these relativizations do not deliver the expected results, and others rely on problematic assumptions. In another broad variety of relativization, cardinality ascriptions are about concepts or sets. The most promising development of this approach is prima facie connected with a violation of the so-called Coreferentiality Constraint, according to which an identity statement is true only if its terms have the same referent. Moreover - even provided that the problem with coreferentiality can be fixed - the resulting analysis of cardinality ascriptions meets several difficulties. (shrink)

In Mathematics is megethology Lewis reconstructs set theory combining mereology with plural quantification. He introduces megethology, a powerful framework in which one can formulate strong assumptions about the size of the universe of individuals. Within this framework, Lewis develops a structuralist class theory, in which the role of classes is played by individuals. Thus, if mereology and plural quantification are ontologically innocent, as Lewis maintains, he achieves an ontological reduction of classes to individuals. Lewis’work is very attractive. However, the alleged (...) innocence of mereology and plural quantification is highly controversial and has been criticized by several authors. In the present paper we propose a new approach to megethology based on the theory of plural reference developed in To be is to be the object of a possible act of choice. Our approach shows how megethology can be grounded on plural reference without the help of mereology. (shrink)

Megethology is the second-order theory of the part-whole relation developed by David Lewis, and it is obtained by combining plural quantification with classical extensional mereology. It can express some hypotheses about the size of the domain such as that there are inaccessibly many atoms. This will prove enough to get the orthodox set theory. Then, megethology is a possible foundation for mathematics. This paper is an introduction to megethology.

In this paper we disambiguate the design stance as proposed by Daniel C. Dennett, focusing on its application to technical artefacts. Analysing Dennett’s work and developing his approach towards interpreting entities, we show that there are two ways of spelling out the design stance, one that presuppose also adopting Dennett’s intentional stance for describing a designing agent, and a second that does not. We argue against taking one of these ways as giving the correct formulation of the design stance in (...) Dennett’s approach, but propose to replace Dennett’s original design stance by two design stances: an intentional designer stance that incorporates the intentional stance, and a teleological design stance that does not. Our arguments focus on descriptions of technical artefacts: drawing on research in engineering, cognitive psychology and archaeology we show that both design stances are used for describing technical artefacts. A first consequence of this disambiguation is that a design stance, in terms of interpretative assumptions and in terms of the pragmatic considerations for adopting it, stops to be a stance that comes hierarchically between the physical stance and the intentional stance. A second consequence is that a new distinction can be made between types of entities in Dennett’s approach. We call entities to which the intentional designer stance is applied tools and entities to which the teleological design stance is applied instruments, leading to a differentiated understanding of, in particular, technical artefacts. (shrink)

The pragmatic logic of assertions shows a connection between ignorance and decidability. In it, we can express pragmatic factual ignorance and first-order ignorance as well as some of their variants. We also show how some pragmatic versions of second-order ignorance and of Rumsfeld-ignorance may be formulated. A specific variant of second-order ignorance is particularly relevant. This indicates a strong pragmatic version of ignorance of ignorance, irreducible to any previous form of ignorance, which defines limits to what can justifiably be asserted (...) about higher-order ignorance. Finally, we relate the justified assertion of second-order ignorance with scientific assertions. (shrink)

Aim of the paper is to revise Boolos’ reinterpretation of second-order monadic logic in terms of plural quantification ([4], [5]) and expand it to full second order logic. Introducing the idealization of plural acts of choice, performed by a suitable team of agents, we will develop a notion of plural reference . Plural quantification will be then explained in terms of plural reference. As an application, we will sketch a structuralist reconstruction of second-order arithmetic based on the axiom of infinite (...) à la Dedekind, as the unique non-logical axiom. We will also sketch a virtual interpretation of the classical continuum involving no other infinite than a countable plurality of individuals. (shrink)

Classical mereology seems unable to characterise the identity conditions of word types. For example, the same letter types ordered differently result in different word types; but mereological fusions of the same letters are identical, regardless of the order of the letters. We show, however, that by combining classical mereology with plural logic one can give a definition of word types that satisfies the identity criteria of word types. This means that it is not necessary to abandon classical mereology in order (...) to give an analysis of the mereological structure of word types. (shrink)

Conflicts between our best philosophical theories (BPTs) and our common beliefs are widespread. For example, if eliminativism is our BPT, then our BPT conflicts with common beliefs about the existence of middle-sized composite artifacts. “Compatibilism” is the name usually given to a theoretical attitude, according to which, in the case of a conflict between BPT and a common belief P, we should try to find a reconciliation. The two major variants of compatibilism are “semantic compatibilism” (SC) and “cognitive compatibilism” (CC). (...) According to SC, to be reconciled with BPT is the “real” version of the content of our ordinary assertions; according to CC, to be reconciled with BPT is the mental state we are “really” in while thinking P. In this paper, we present a new kind of compatibilism, epistemic compatibilism (EC). According to EC, to be reconciled with BPT is the explanation of why we believe that P. After presenting EC, we will argue that it fares better than SC and CC for at least two related reasons: EC does not rely on any form of what we call semantic or cognitive “recarving”; thus, EC avoids some sceptical problems that aect the other two versions of compatibilism. (shrink)

The Knowability Paradox is a logical argument showing that if all truths are knowable in principle, then all truths are, in fact, known. Many strategies have been suggested in order to avoid the paradoxical conclusion. A family of solutions –ncalled logical revision – has been proposed to solve the paradox, revising the logic underneath, with an intuitionistic revision included. In this paper, we focus on so-called revisionary solutions to the paradox – solutions that put the blame on the underlying logic. (...) Specifically, we analyse a possibile translation of the paradox into a modified intuitionistic fragment of a logic for pragmatics inspired by Dalla Pozza and Garola in 1995. Our aim is to understand if KILP is a candidate for the logical revision of the paradox and to compare it with the standard intuitionistic solution to the paradox. (shrink)

Relativists maintain that identity is always relative to a general term. According to them, the notion of absolute identity has to be abandoned and replaced by a multiplicity of relative identity relations for which Leibniz’s Law does not hold. For relativists RI is at least as good as the Fregean cardinality thesis, which contends that an ascription of cardinality is always relative to a concept specifying what, in any specific case, counts as a unit. The same train of thought on (...) cardinality and identity is apparent among those – Artifactualists – who take relative identity sentences for artifacts as the norm. The aim of this paper is to criticize the thesis thatfrom FC it is possible to derive RI, and to explain why Artifactualists mistakenly believe that RI can be derived from FC. The misunderstanding derives from their assumption that the concept of artifact – like the concept of object – is not a sortal concept. (shrink)

The aim of this note is to discuss the general form and role of identity criteria. We have taken two readings into consideration which express two different functions of identity criteria. The first expresses the epistemic function whilst the second deals with the ontological function. We argue that there are several problems related to the specification of both these functions. As a consequence, we conclude that identity criteria are not necessary to provide ontological legitimacy.

The general question (G) How do we categorize artifacts? can be subject to three different readings: an ontological, an epistemic and a semantic one. According to the ontological reading, asking (G) is equivalent to asking in virtue of what properties, if any, a certain artifact is an instance of some artifact kind: (O) What is it for an artifact a to belong to kind K? According to the epistemic reading, when we ask (G) we are investigating what properties of the (...) object we exploit in order to decide whether a certain artifact belongs to a certain kind. (G) thus becomes: (E) How can we know that artifact a belongs to kind K? Finally, (G) can also be read as a question concerning the semantics of artifact kind terms. The semantic reading of (G) is: (S) What kind of reference do artifact kind terms have, if any? In this editorial we expand on the different answers to (O), (E) and (S) that are given in the selected literature on the topic. The result should give us an overall picture of the possible answers to (G). (shrink)

The present paper is devoted to present two pragmatic logics and their corresponding intended interpretations according to which an illocutionary act of hypothesis-making is justified by a scintilla of evidence. The paper first introduces a general pragmatic frame for assertions, expanded to hypotheses, ${\mathsf{AH}}$ and a hypothetical pragmatic logic for evidence ${\mathsf{HLP}}$. Both ${\mathsf{AH}}$ and ${\mathsf{HLP}}$ are extensions of the Logic for Pragmatics, $\mathcal{L}^P$. We compare ${\mathsf{AH}}$ and $\mathsf{HLP}$. Then, we underline the expressive and inferential richness of both systems in (...) dealing with hypothetical judgements, especially when based on different, sometimes conflicting, evidence. (shrink)

Per il dialeteismo ci sono contraddizioni vere. Questa concezione filosofica ha assunto una forma chiara e definita a partire dal lavoro del filosofo e logico Graham Priest – uno dei suoi padri fondatori, nonché uno dei suoi più strenui difensori. Questo libro intende portare il dialeteismo all’attenzione di un ampio pubblico, che non sia solo quello degli addetti ai lavori. Il volume è suddiviso in due parti. La prima include le cinque lezioni su "Dialeteismo e storia della filosofia" tenute da (...) Priest e Filippo Casati a Padova nel 2016, in occasione del Corso di Eccellenza per il dottorato in filosofia dell’Università di Padova. La seconda contiene quattro contributi sul dialeteismo di autori italiani. (shrink)

What kind of reference (if any) do terms such as “pencil,” “chair,” “television,” and so on have? On the matter, a de-bate between directly referential theorists and descriptiv-ist theorists is open. It is largely acknowledged that natural kind terms (such as “water,” “gold,” “tiger,” etc.) are directly referential expressions (cf. Putnam,1975). That is, they are expressions whose reference is determined by their refer-ents' nature, independent of whether we know or will ever know what this nature is. However, it does not (...) seem like-wise convincing that all artifactual kind terms (like “pen-cil,” “chair,” “television,” etc.) semantically behave the same. Terms for artifactual kinds seem more likely to be subjected to a descriptivist view, that is, definable not by links to their extensions' nature but in terms of conjunctions or clusters of properties. In his celebrated “The Meaning of ‘Meaning’” (1975), Hilary Putnam originated the mentioned debate by arguing that artifactual kind terms also refer directly. Thus, the discussion ultimately revolves around establishing whether artifactual and natural kind terms are both directly referential expressions. The authors engaged in this debate have tried to argue in favor of (or against) Putnam's proposal by highlighting the similarities (or differences) between nat-ural vis-à-vis artifactual kind words and their respective ref-erents. This paper aims to provide a thorough and reasoned overview of the debate at stake, pointing out trends and problems associated with each proposed account. (shrink)

The goal of the paper is to analyse some specific features of a very central concept for top-level ontologies for information systems: i.e. the concept of artefact. Specifically, we analyse the relation to be a copy of that is strongly linked to the notion of artefact and—as we will demonstrate—could be useful to distinguish artefacts from objects of other kinds. Firstly, we outline some intuitive and commonsensical reasons for the need of a clarification of the notion of artefact in ontologies (...) for information systems, and we analyse some characterisations of the notion given by two top-level ontologies (Cyc and Wordnet). Secondly, we introduce and critically analyse Tzouvaras’ notion of copy. Thirdly, we try to complete an analysis of copy by distinguishing three kinds of copies: replicas (Tzouvaras’ notion of copy), rigid copies, and functional copies. With the help of these three notions we outline a first and preliminary distinction between artefacts, objects of art and natural objects. (shrink)

This is an excerpt from the contentIn the introduction to part I of the symposium we stated that a rational agent could be thought of as an agent who has good reasons for its actions. In formal analyses of economic, medical, political, military and forensic decisions rationality, that is the “goodness” of those reasons, is inextricably intertwined with probability. Typically, those analyses concern decisions in a particular class of uncertain situations, namely “risky” situations, where all the relevant available alternative actions (...) are known, each or most actions are non-deterministic , and the probability of each outcome is known to some degree of approximation. As yet, formal analyses have only begun to scratch the surface of the subtleties implicated in uncertain, but not risky, situations, where the available courses of actions, and/or their possible outcomes, and/or the probabilities of those outcomes, are not all. (shrink)

A popular stance amongst philosophers is one according to which, in Lewis’ words, “identity is utterly simple and unproblematic”. Building from Lewis’ famous passage on the matter, we reconstruct, and then criticize, an argument to the conclusion that identities cannot be grounded. With the help of relatively uncontroversial assumption concerning identity facts, we show that not all identities are equi-fundamental, and, on the contrary, some appear to be provided potential grounding bases using two-level identity criteria. Further potential grounding bases for (...) identities are presented. Identity might be utterly simple and unproblematic, but this is not sufficient to conclude that identities are ungrounded, or fundamental. (shrink)

In this paper we consider the emerging position in metaphysics that artifact functions characterize real kinds of artifacts. We analyze how it can circumvent an objection by David Wiggins (Sameness and substance renewed, 2001, 87) and then argue that this position, in comparison to expert judgments, amounts to an interesting fine-grained metaphysics: taking artifact functions as (part of the) essences of artifacts leads to distinctions between principles of activity of artifacts that experts in technology have not yet made. We show, (...) moreover, that our argument holds not only in the artifactual realm but also in biology: taking biological functions as (part of the) essences of organs leads to distinctions between principles of activity of organs that biological experts have not yet made. We run our argument on the basis of analyses of artifact and biological functions as developed in philosophy of technology and of biology, thus importing results obtained outside of metaphysics into the debate on ontological realism. In return, our argument shows that a position in metaphysics provides experts reason for trying to detect differences between principles of activities of artifacts and organs that have not been detected so far. (shrink)

According to N. Goodman, the Carnapian notion of similarity is useless in science and without interest for philosophy. In our paper we suggest that, given the current role that the notion of similarity has in managing biomedical big data, this drastic position should be revised, and similarity should be provided a scientifically useful philosophical interpretation. With the advent of the new sequencing technologies, imaging technologies and with the improvements of health records, the number of genomics, post-genomics and clinical data has (...) exponentially increased. The deluge of data has urged, among others, to devise a new way of stratifying patients. A solution has been found and it is based exactly on the notion of similarity. By discussing two examples focusing on similarity among breast cancer patients, in the paper we illustrate such a use, and analyze it from a philosophical standpoint by resorting to A. Tversky’s features matching approach. We believe that the latter can foster some better understanding of the meaning and current use of similarity in the context of biomedical big data, and that, therefore, be the focus of further reflections in the philosophy of science, in particular in the philosophy of biomedicine. (shrink)

In Parts of Classes David Lewis attempts to draw a sharp contrast between mereology and set theory and he tries to assimilate mereology to logic. For him, like logic but unlike set theory, mereology is “ontologically innocent”. In mereology, given certain objects, no further ontological commitment is required for the existence of their sum. On the contrary, by accepting set theory, given certain objects, a further commitment is required for the existence of the set of them. The latter – unlike (...) the sum of the given objects – seems to be an abstract entity whose existence is not directly entailed by the existence of the objects themselves. The argument for the innocence of mereology is grounded on the thesis of composition as identity. In our paper we argue that: arguments for the ontological innocence of mereology are not conclusive. Some arguments against the ontological innocence of mereology show a certain ambiguity in the innocence thesis itself. The innocence thesis seems to depend on a general conception of the nature of objects and on how the notion of ontological commitment is understood. Specifically, we think that the thesis is the manifesto of a realistic conception of parts and sums. Quine‟s notorious criticism of the set-theoretical interpretation of second order logic seems to be reproducible against Lewis‟defence of mereology. To the purpose we construct a mereological model of a substantive fragment of set theory, adequate to ground the set-theoretical semantics of second order logic. (shrink)

P.T. Geach has maintained (see, e.g., Geach (1967/1968)) that identity (as well as dissimilarity) is always relative to a general term. According to him, the notion of absolute identity has to be abandoned and replaced by a multiplicity of relative identity relations for which Leibniz's Law - which says that if two objects are identical they have the same properties - does not hold. For Geach relative identity is at least as good as Frege's cardinality thesis which he takes to (...) be strictly connected with relative identity - according to which an ascription of cardinality is always relative to a concept which specifies what, in any particular case, counts as a unit. The idea that there is a close connection between relative identity and Frege's cardinality thesis has been issued again quite recently by Alston and Bennett in (1984). In their opinion, Frege's cardinality thesis is not only similar to relative identity - as Geach maintains - but it implies it. Moreover, they agree with Geach in claiming that a commitment to Frege's cardinality thesis forces a parallel commitment to relative identity. Against Geach, Alston and Bennett we will claim that (Tl): "Frege's cardinality thesis is similar to relative identity" is false and that therefore (T2) "Frege's cardinality thesis implies relative identity" is false as well. (shrink)

In Mathematics is megethology. Philosophia Mathematica, 1, 3–23) David K. Lewis proposes a structuralist reconstruction of classical set theory based on mereology. In order to formulate suitable hypotheses about the size of the universe of individuals without the help of set-theoretical notions, he uses the device of Boolos’ plural quantification for treating second order logic without commitment to set-theoretical entities. In this paper we show how, assuming the existence of a pairing function on atoms, as the unique assumption non expressed (...) in a mereological language, a mereological foundation of set theory is achievable within first order logic. Furthermore, we show how a mereological codification of ordered pairs is achievable with a very restricted use of the notion of plurality without plural quantification. (shrink)

The aim of this paper is twofold: First, we present and develop a system of logic for pragmatics including the act of denial. Second, we analyse in our framework the so-called paradox of assertability. We show that it is possible to yield sentences that are not assertable. Moreover, under certain conditions, a symmetric result can be obtained: There is a specular paradox of deniability. However, this paradox is based on the problematic principle of classical denial equivalence.

The pragmatic notion of assertion has an important inferential role in logic. There are also many notational forms to express assertions in logical systems. This paper reviews, compares and analyses languages with signs for assertions, including explicit signs such as Frege’s and Dalla Pozza’s logical systems and implicit signs with no specific sign for assertion, such as Peirce’s algebraic and graphical logics and the recent modification of the latter termed Assertive Graphs. We identify and discuss the main ‘points’ of these (...) notations on the logical representation of assertions, and evaluate their systems from the perspective of the philosophy of logical notations. Pragmatic assertions turn out to be useful in providing intended interpretations of a variety of logical systems. (shrink)